Never pay down a deposit in a bank account until you have met the seller, seen signed a purchase agreement.
No serious private advertisers ask for a down payment before you meet.
Receiving an email with an in-scanned ID does not mean that you have identified the sender. You do this on the spot, when you sign a purchase agreement.
Selling books and board games: Pynchon “Gravity's Rainbow” (new) - 1200 dinars, Remarque “Arch of Triumph” (used) - 200 dinars, Remarque “All Quiet on the Western Front…” (used) - 200, Zusak “The Book Thief” (used) - 200, History of Serbia (in English) - 500, Pop Art Puzzle (open, all parts in place) - 1500, Imaginarium light - 1700